1. **State the problem:** We need to select the equation that best represents the first model (bottom-left) where the scale has one star on the left and three rectangles on the right. The legend shows star = $m$ and rectangle = 1. 2. **Analyze the model:** The left side has 1 star, so its value is $m$. The right side has 3 rectangles, each worth 1, so total value is $3 \times 1 = 3$. 3. **Form the equation:** Since the scale is balanced, left side equals right side: $$m = 3$$ 4. **Check the options:** - A) $3 + m = 9$ (incorrect) - B) $3 + 3m = 9$ (incorrect) - C) $3m = 9$ (incorrect) - D) $3, m = 9$ (not a valid equation) None of these exactly match $m=3$, but option C) $3m=9$ simplifies to $m=3$ by dividing both sides by 3: $$\frac{\cancel{3}m}{\cancel{3}} = \frac{9}{3}$$ $$m = 3$$ Therefore, option C) $3m=9$ best represents the model. **Final answer:** Option C) $3m=9$